Senior Full-stack AI Engineer

Toyo; United States; Remote; USD 140,000 - 228,000; Full time

Benefits offered by this job

Remote-first position

Job summary

Toyo is seeking a senior software engineer to build the full-stack infrastructure that enables AI agents to carry out ongoing business workflows safely and reliably. This senior individual-contributor role blends hands-on engineering with architectural decisions across agent execution and the underlying services needed to support a growing platform.

As part of a small team, you design agent session and communication systems, including persistent state and long-running workflows, and develop

Qualifications

• Senior-level software engineering experience with hands-on work across the stack.
• Ability to design production systems with evolving requirements.
• Thoughtful approach to security including credential isolation and prompt-injection defenses.
• Willingness to make architectural decisions in an early-stage environment.

Responsibilities

• Design and build agent session and communication systems with persistent state and long-running workflows.
• Develop platform primitives such as isolated compute, durable data storage, and secure credential handling.
• Make agent actions dependable and safe, addressing risks like prompt injection and unsafe outputs.
• Collaborate across the product stack to scale infrastructure from early customer use to a full platform.
• Contribute code and shape technical direction with the founding team.

Skills

Senior-level software engineering

Hands-on across the stack

Architectural design

Agent security awareness

Job description

Role overview

Build the full-stack infrastructure that lets AI agents carry out ongoing business workflows safely and reliably. This senior individual-contributor role combines hands-on engineering with architectural decisions, spanning agent execution and the underlying services needed to support a growing platform.

Responsibilities

• Design and build agent session and communication systems, including persistent state and workflows that continue over time.
• Develop platform primitives such as isolated compute, durable data storage, and secure credential handling.
• Make agent actions dependable and safe, addressing risks such as prompt injection and unsafe outputs.
• Work across the product stack to take infrastructure from early customer use toward a scalable platform.
• Collaborate directly with the founding team, contributing code and shaping technical direction.

Requirements

• Senior-level software engineering experience and willingness to work hands-on across the stack.
• Strong judgment in designing and delivering production systems with limited process and evolving requirements.
• A thoughtful approach to agent security, including credential isolation, output sanitization, and prompt-injection defenses.
• Comfort making architectural decisions and solving open-ended problems in an early-stage environment.
• Availability to work remotely in the Eastern time zone; Canadian candidates are preferred.

Benefits and work setup

• Full-time, remote-first role with a stated salary range of CAD $200,000–$325,000, plus benefits and equity.
• Direct influence on product and architecture, within a small team with low process overhead.
• An annual week-long team gathering; the role description says the location varies.